hello all, first thread here...

did a search, didn't find anything relevant to my situation.

ok, so here is the deal. i have a 2006 expedition limited, with a tad over 53k miles. while i was driving at approximately 65mph the other night, i noticed the speedo needle was starting to drop, and then go back to the speed i was traveling. looked at all the other gauges, and everything was fine. engine temp was fine, battery was fine, oil pressure was fine. shortly after that (within a minute or so), the check engine light came on, the display said "engine failsafe mode", the "o/d off" light started flashing, and the speedo dropped to 0. the engine went into limp mode, so i pulled over to the side of the road to check things out. there was plenty of coolant, oil was full, transmission fluid was full.

so i started the motor again, and it was the same. "engine failsafe mode" showed on the display, the check engine light was on, the "o/d off" light was flashing, and the engine was in limp mode. i was about an hour from home, so i called a tow truck, and got the truck home.

so i borrowed an obd2 code scanner from a buddy, and got 2 codes. i got P0720, which appears to be an output shaft speed sensor issue, and P2106, which appears to be a throttle actuator control system issue.

with some more research, i came to the conclusion that the p0720 code (output shaft speed sensor) is an in-depth detail of the p2106 code. so i am thinking it is safe to assume that my issue is with the output shaft speed sensor...

i have read the sensor is on top of the transmission housing in the back, and to trace the wiring from the sensor to the pcm to chack for any shorts. i have also read to check the wiring under the steering column, behind the gearshift lever, for shorts.

is there anything else i need to check, or is my diagnosis off, or does anyone have any other advice for me on this situation?

thanks...

 

anyone? please?

 

I think your diagnosis is spot on.

 

dont disregard the throttle code. the 3v's are very common to need replacement of the tps, and sometimes the complete electronic throttle body (which includes a new tps). i work for ford, and have seen more than my fair share of them.

 

hmm... ok, i will look into that. thanks.